Adjustable diaphragm pump



Sept. 22, 1964 w, E. DAVIS 3,149,572

ADJUSTABLE D'IAPHRAGM PUMP INVENTOR. William E. Davis B1w Mw ATTORNEYS Sept. 22, 1964 Filed Nov. 13, 1961 FIG. 2.

W. E. DAVIS ADJUSTABLE DIAPHRAGM PUMP 5 Sheets-Sheet 2 INVENTOR.

William E. DOVS ATTORNEYS 3 Sheets-Sheet 5 Filed Nov. 13. 1961 FIG.

INVENTOR. william E. Davis 7er-lt ATTORNEYS United States Patent O 3,149,572 ADJUSTABLE DIAPHRAGM PUMP Wilhiam E. Davis, Seven Springs, N C. Filed Nov. 13, 1961, Ser. No. 151,964 Claims. (Cl. 10S-37) The present invention concerns an adjustable diaphragm positive displacement liquid pump.

It is an object of the invention to provide a pump of small stroke and long life. c

It is an object of the invention to provide a diaphragm pump having an adjustment by which the effective portion of the diaphragm may be adjusted to vary the volume of water pumped in a given period.

It is an object of the invention to provide ram tuning as part of a pump structure to maximize the pump eiciency and the volume of liquid which can be pumped per unit of time.

It is an object of the invention to provide means .to compress the diaphragm of a liquid pump to vary the displacement. l

It is an object of the invention to provide an intake air cushion which can be adjusted to allow for a plurality of factors such as frequency of stroke, length of stroke, height of lift, pipe friction and restrictions.

It is an object of the invention to provide a liquid pump which is simple to construct, easily serviced and has a long trouble-free life.

It is an object of the invention to reduce the number of parts in a uid pump to a minimum and to make all parts readily accessible.

diaphragm It is an object of the invention to provide a fluid pumpv with a simple valve construction. Other objects of the invention will appear from a reading of the specification and drawing in which like numerals refer to like parts throughout.

In the drawings:

FIGURE 1 is a side elevation of a pump constructed according to the invention.

FIGURE 2 is an end elevation of the pump of FIG- URE 1 with part cut away to show ram tuning.

FIGURE 3 is a fragmentary showing in section of the diaphragm and valve construction according to the invention.

FIGURE 4 is an exploded View of the diaphragm assembly.

FIGURE 5 is a fragmentary view of the diaphragm assembly at the end of a pumping stroke, showing the diaphragm adjustment for maximum life.

FIGURE 6 is a fragmentary view of the diaphragm assembly adjusted to increase the volume of water pumped.

The pump has a frame 10 which mounts a suitable electric motor 11 supplied from control 12 for driving a iiywheel I3 by means of V belt 14. Flywheel 13 is mounted for rotation on shaft 15 which carries an eccentric 16 having about a half inch throw. A relatively long connecting rod 17 has a bearing 1S in one end and is mounted on and is driven by the eccentric 16. The other end of connecting rod 17 is enlarged into a stirrup 19 having an outwardly facing curved surface 20, the center of whichis drilled to receive a bolt 21 having a counter-sunk head and a nut 22.

Frame 1 0 has a housing memberl comprising three parts, 23, 24 and 25, bolted together with valve plate 26 mounted between the outer two. Front part 23 has an enlarged front end through which the stirrup 19 freely passes. Part 23 has an annular recess which receives a thick Neoprene diaphragm 27 which is held in place by part 24. A Teflon washer 23 is placed between rounded surface 20 and diaphragm 27 to prevent chafng, galling and undue wear. The curved surface may be coated with Teflon if desired. Although another Teflon washer can be used 3,149,572 Patented Sept. 22 1964 ICC on the opposite side of diaphragm 27 it is really not necessary because the liquid being pumped lubricates that side. A curved member 30 is mounted on the liquid side of diaphragm 27 with its curved side adjacent diaphragm 27. A simple flat valve plate 26 is mounted between parts 24 and 25, the diaphragm-valve assembly being held together by bolts 2% which may be readily disassembled. Valve 26 has spaced holes which are covered with simple discs biased to closed position by coil springs. This valve construction is simple, does not readily foul, is easily cleaned, and has a long life.

Part 25 has an intake chamber 31 and an output chamber 32 both covered by valve plate 26 with a valve hole leading to each chamber. Output chamber 32 is connected to an air chamber 33, comprising a tube 34 provided with an adjustable plunger 35 `for varying the volume of air chamber 32, to provide ram tuning. A threaded member 36 connects plunger 35 for adjustment by wing nut 37. Member 36 is mounted within a sleeve 38 which is fixed inside tube 34, the cap 40 closing tube 34.

The operation of the pump is as follows:

Control 12, which contains a line switch, places motor 11 across the line and it drives flywheel 13 through belt 14. Shaft 15 rotates eccentric 16 to drive connecting rod 17 and reciprocate flexible diaphragm 27.

Connecting rod 17 has about one-half inch of travel and reciprocates iexible diaphragm 27 which is preferably about live or six inches diameter and is about threeeighths to a half inch thick. As diaphragm 27 is anchored around its periphery and bolted to the center of curved surface 20 on the end of stirrup 19 of rod 17, its center is free to move with curved surface 20. The eccentric 16 moves rod 17 back and forth and also rocks it through a small angle, so that curved surface 20 tends to roll on diaphragm 27, any friction being minimized by Teflon washer 28. It will be seen that the center of diaphragm experiences the maximum pumping movement which decreases to zero at the edges.

To increase the pumping action bolt 21 is tightened, pressing member 30 and rounded surface 2t) toward each other so that they sink into the Neoprene material of diaphragm 27 and cause an increased area to move through a greater distance. This will appear from a comparison of the diaphragm 27 in FIGURE 5 with the same diaphragm 27 in FIGURE 6, wherein the connecting element 21 has been tightened anda larger central area of the diaphragm is forced to move through the maximum stroke distance in both directions. Connecting element 21 thus provides what may be called a metering adjustment of the pump as it provides a means to control pumping capacity within close limits. This is not intended to be a major adjustment, but a minor one. For example, after an installation is made to perform a specific pumping operation and it is found to be under specification, a tightening of bolt 21 can increase the pump output up to five percent.

The expansion chamber 33 is adjustable so as to maximize the efficiency of the pump. The optimum size of chamber 33 is determined by frequency of stroke, length of stroke, height liquid is lifted, length of intake pipe, restrictions in pipe, size of pipe, viscosity of liquid being pumped, etc. When the chamber 33 is too small, hammer occurs which is noisy, can damage the pump and causes inefficient operation. When chamber 33 is too large, lwater is not effectively pumped. When the size of chamber 33 is adjusted by plunger 35 and nut 37 to a position such that chamber 33 is a little larger than the size which causes hydraulic hammer, liquid continues to move into the intake pipe 31 at the end of the. stroke -lar water supply is desired, temperature responsive for fire prevention, a manual switch, or the like.

While there have been described above what are presently believed to be the preferred forms of the invention,

variations thereof will be obvious to those skilled in the art and all suchchanges and variations which fall within the spirit of the invention are intended to be covered by the generic terms in the appended claims, which are variably worded to that end.

I claim:

1. The combination in a diaphragm pump for pumping liquids, a frame, a iexible diaphragm anchored around its periphery to said frame, a connecting rod for connecting said driving means and said diaphragm in operative relation, said rod having a convexlycurved end surface of substantial area, a convexly curved backing member, said backing member being positioned with its convex curvature facing said curved end surface, said diaphragm having substantial thickness and compressibility and being positioned between said convexly curved surfaces, adjustable connecting means for holding said convexly curved surfaces and said diaphragm in Contact and having a movable part constructed to vary the area of said Contact and thereby to adjust the size of the central area of said diaphragm in firm Contact with said curved surfaces, said adjustable connecting means'being accessible from the outside of said frame whereby the pump capacity can be adjusted Without the removal of any part of said frame, said connecting rod having an enlarged stirrup at its diaphragm end for supporting said curved surface with spacedlegs, said movable part of said connecting means being positioned between the legs of said stirrup.

2. The combination' set forth in claim 1, said connecting rod having a small stroke, the curvature of said curved surface being so related to the length of said connecting rod and to the distance of travel of said rod that said curved surface tends to roll on said exible diaphragm decreasing localized twisting thereof and plastic means between said curved surface of said connecting rod and said flexible diaphragm and conforming to said curved surface, thereby increasing the useful life of said diaphragm.

3. The combination set forth in claim 2, said plastic means comprising a coating of Teflon on said vcurved surface.

4. In combination in a diaphragm pump for pumping liquids, a frame, a thick iiexible diaphragm fastened to said frame, drive means, a connecting rod for connecting said drive means and said diaphragm in operative relation, said rod having a curved end surface, means for joining the center of said curved surface and the center of said diaphragm together and constructed to cause said curved surface to deform said diaphragm adjacent its central portion by forcing at least part of the curvature of said curved surface against the material of said thick diaphragm to decrease the thickness of said diaphragm at the area of deformation, and plastic means separate from said diaphragm and positionedl between said diaphragm and said curved surface, said plasticmeans being capable of conforming to the curvature of said curved surfaceand being in fixed Contact with said diaphragm only at the center thereof adjacent said joining means, said plastic -meanshavinga portion spaced from its center which is located between said end surface and said diaphragm and which is pressed into engagement with said diaphragm when the rod moves in one direction and is pulled from contact with said 'diaphragm when the rod moves in the other direction to thereby protect the diaphragm and increase its life.

5. The combination set forth in claim 4, said plastic means comprising a coating of Teflon adhering to said curved surface of said connecting rod.

References Cited in the tile of this patent UNITED ASffATl-IS PATENTS 1,484,115 Eells Feb. 19, 1924 1,976,098 Smith Oct. 9, 1934 2,100,404 Mason et al Nov. 30, 1937 2,117,563 McMillan May 17, 1938 2,145,566 Corydon et al. Jan. 31, 1939 2,148,957 Morris etal Feb. 28, 1939 2,157,132 Joy May 9, 1939 2,185,784 Corydon et al. Jan. 2, 1940 2,674,954 Colbert Apr. 13, 1954 2,687,696 Theis Aug. 31, 1954 2,736,332 Simmonsy Feb. 2S, 1956 2,777,029 Langstroth Ian. 8, 1957 k FOREIGN PATENTS 666,760 VGermany Oct. 27, 1938 OTHER REFERENCES Pump Questions and Answers, chapter 18, McGraw- Hill Book Co., 1949. 

1. THE COMBINATION IN A DIAPHRAGM PUMP FOR PUMPING LIQUIDS, A FRAME, A FLEXIBLE DIAPHRAGM ANCHORED AROUND ITS PERIPHERY TO SAID FRAME, A CONNECTING ROD FOR CONNECTING SAID DRIVING MEANS AND SAID DIAPHRAGM IN OPERATIVE RELATION, SAID ROD HAVING A CONVEXLY CURVED END SURFACE OF SUBSTANTIAL AREA, A CONVEXLY CURVED BACKING MEMBER, SAID BACKING MEMBER BEING POSITIONED WITH ITS CONVEX CURVATURE FACING SAID CURVED END SURFACE, SAID DIAPHRAGM HAVING SUBSTANTIAL THICKNESS AND COMPRESSIBILITY AND BEING POSITIONED BETWEEN SAID CONVEXLY CURVED SURFACES, ADJUSTABLE CONNECTING MEANS FOR HOLDING SAID CONVEXLY CURVED SURFACES AND SAID DIAPHRAGM IN CONTACT AND HAVING A MOVABLE PART CONSTRUCTED TO VARY THE AREA OF SAID CONTACT AND THEREBY TO ADJUST THE SIZE OF THE CENTRAL AREA OF SAID DIAPHRAGM IN FIRM CONTACT WITH SAID CURVED SURFACES, SAID 